Head suspensions for supporting a head over a rotating disk in hard disk drives are well known. Such head suspensions typically comprise a load beam having a flexure or gimbal at its distal end. A head slider having a read/write transducer is mounted to the flexure. Conductive leads or traces are integrated with the head suspension and connect the read/write transducer to disk drive circuitry via terminal or bond pads. In operation, the rotating disk creates an air bearing on which the head slider floats. The head suspension provides a spring force counteracting the force generated by the air bearing to position the slider at a specified “fly height”. The flexure is sufficiently compliant to allow the slider to pitch and roll in response to fluctuations in the air bearing created by variations in the surface of the rotating disk. In this manner, the head slider is supported and can be positioned over the disk by an actuator assembly in the drive to read or write information on the disk.
The use of a dimple, formed in a surface of the head suspension, is also well known. Dimples are used to transfer the spring force generated by the head suspension to the slider and to provide a point about which the slider can move or gimbal in pitch and roll directions at the fly height. Such dimples are referred to as “load point dimples” or “load points” and can be formed in a spring metal member or “tongue” of the flexure to which the slider is mounted. Accurate positioning of the head slider with respect to the load point and the terminal pads is important to the function of the disk drive.
Load point dimples are typically formed by forming or etching processes or by fixing a spherical ball between the flexure and load beam. Examples of such load point structures are shown in U.S. Pat. Nos. 4,167,765 to Watrous; 5,428,490 to Hagen; and 6,181,522 to Carlson. Load points such as those described in the above references have certain disadvantages owing to deformation caused by forming or stack-up of positional tolerances in head suspension assembly operations.
There is a continuing need for improved load points in head suspensions. Specifically, there is a need for a load point and related manufacturing processes that can be precisely located with respect to trace terminal pads and imparts minimal stresses to the surface on which it is located. To be commercially viable, any such load point should be capable of being efficiently manufactured.